The disclosure is directed to a device and method to insert print image-dependent prefire pulses in an inkjet printing system.
Inkjet printing systems may be used to print to recording media (such as paper, for example). For this, a plurality of nozzles may be used in order to fire or push ink droplets onto the recording medium, and thus in order to generate a desired print image on the recording medium.
During printing, print quality problems (for example an incorrect positioning of an ink droplet or a nozzle failure) may occur depending on the type of ink that is used and/or depending on the print speed and/or depending on the ejected droplet size per nozzle. These print quality problems typically arise due to the increase of the viscosity of the ink in the nozzle. In particular, what are known as first line effects—in which print dots may no longer be placed in a targeted manner on the recording medium by a nozzle, or the nozzle fails completely—may occur after longer print pauses due to the viscosity change of the ink in a nozzle.
Prefire pulses can be used to reduce and/or eliminate quality issues. Prefire pulses produce a stirring of the ink in the nozzle channel of a nozzle arrangement immediately behind the nozzle opening, and thus prevent a drying out of a nozzle arrangement that has not been used for a period of time. No (non-white) print dots are generated on the paper by prefire pulses.